Such temperature regulator frequently used includes one composed essentially of an aluminum block, and there is known one in which the aluminum block is heated with a heater or one in which the aluminum block is cooled with a refrigerant flowing through a refrigerant channel. There is another type of temperature regulator which carries out both heating and cooling in one aluminum block for applications in tests which require cooling after heating or vice versa. The temperature regulator carrying out both heating and cooling in one aluminum block includes, for example, one resorting to a peltier device or to a low and high temperature external circulating system having a combination of a refrigerant circulating system and a heating coil, and one having an aluminum block provided with a refrigerant channel and a heater attached to the aluminum block.
However, the temperature regulator resorting to a peltier device failed to provide effective means, since the device involves problems that it has insufficient power relative to the quantity of sample contained in each sample container and cannot provide a sufficient temperature range, and that the device is expensive and has poor durability. In the temperature regulator resorting to a low and high temperature external circulating system, its possible temperature regulating range depends upon the kind of the fluid to be circulated (circulating fluid), and in the case of circulating fluid commonly used have temperature regulating ranges of −60° C. to +65° C., −40° C. to +120° C., +10° C. to +200° C. and +50° C. to +250° C. respectively. A temperature control beyond these ranges requires replacement of the circulating fluid. In addition, in the case of the low and high temperature external circulating system, the temperature of several liters of circulating fluid must be changed when the preset temperature range is to be changed, and the speed of increasing and decreasing the temperature is extremely low. Thus, a plurality of sample containers set in one aluminum block are caused to have the same temperature. Therefore, if temperatures of a plurality of sample containers are to be regulated at different levels, it requires a plurality of aluminum blocks heated or cooled to different temperatures, respectively.
In the temperature regulator having an aluminum block provided with a refrigerant channel and a heater attached to the aluminum block, the refrigerant in the refrigerant channel deprives of the heat of the heater, when the aluminum block is heated after cooling, to lower the heating rate of the aluminum block and to increase the temperature of the refrigerant, lowering cooling efficiency of the refrigerant circulating system. In addition, in this temperature regulator, if the heating temperature is higher than the boiling point of the refrigerant, the heating causes boiling of the refrigerant. Therefore, heating must be carried out after the refrigerant is discharged, or the refrigerant must be replaced with one having a higher boiling point.
Further, in the temperature regulator having an aluminum block provided with a refrigerant channel and a heater attached to the aluminum block, the heater gives a large quantity of heat to the refrigerant. Therefore, in the case where a plurality of aluminum blocks are arranged and are set to have different temperatures respectively, if there is a very great difference between the preset temperatures of the adjacent aluminum blocks, these aluminum blocks influence each other through the refrigerant, impeding accurate temperature regulation. Therefore, it is difficult to maintain the aluminum blocks at different temperatures respectively for a long time unless the preset temperature ranges in the aluminum blocks do not differ greatly.
Further, it is not desired in an organic synthesis experiment that vaporized components formed by the heat of reaction mixtures in a sample container be released into the atmosphere. Therefore, a refluxing treatment is necessary so as to convert the vaporized component into the form of liquid and return it to the sample container by cooling a glass reflux column attached to the top of the sample container. In the case where a plurality of sample containers are subjected to refluxing treatment, a cooling mechanism including a water cooling pipe is attached to the reflux column mounted on each sample container, so that the greater the number of the sample containers is, the more troublesome become installation and removal of the reflux columns and cooling mechanisms. Besides, if the sample containers each having a reflux column and a cooling mechanism are subjected as such to shaking, a strong shaking treatment can break the reflux columns and the cooling mechanisms.
A first object of the present invention is to provide a durable sample temperature regulator having a wide temperature regulating range, high heating capacity and high cooling capacity and also having a simple and compact structure.
A second object of the present invention is to provide a sample temperature regulator capable of regulating temperatures of a plurality of samples independent of one another.
A third object of the present invention is to provide a sample temperature regulator, which can also achieve refluxing treatment of samples.